Carboxyl terminal activating region 3 of latent membrane protein 1 encoded by the Epstein‑Barr virus regulates cell proliferation and protein expression in NP69 cells

Abstract

in the present study, the mechanism by which carboxyl terminal activating region 3 (cTar3) of latent membrane protein 1 (lMP1), encoded by the epstein-Barr virus, regulated cell proliferation and protein expression was investigated in the nasopharyngeal epithelial cell line nP69. The deletion mutant lMP1 (lMP1 Δ232-351 ; amino acid residues including 232-351 codons in cTar3 deleted) was generated by polymerase chain reaction. an nP69-lMP1 Δ232-351 cell line was established by retroviral infection. Finally, cell proliferation and protein expression of nP69 cells expressing lMP1 Δ232-351 were examined using a cell growth curve and western blot analysis. The results demonstrated: i) The proliferation of nP69-lMP1 Δ232-351 cells was significantly decreased compared with cells expressing wild type lMP1 (lMP1 WT ; n=3; P<0.05); ii) 17 proteins exhibited differential protein expression (>2-fold change) in nP69-lMP1 Δ232-351 cells compared with nP69-lMP1 WT cells; and iii) lMP1 WT was involved in activating the Janus kinase 3 (JaK3) promoter and regulating the expression of JaK3 protein, while lMP1 Δ232-351 was almost defective in ability to activate the JaK promoter. These results suggested that lMP1-cTar3 may be an important functional domain for regulating cell proliferation and protein expression in nasopharyngeal epithelial cells.

YB1 associates with oncogenetic roles and poor prognosis in nasopharyngeal carcinoma

“…All cell lines were recently authenticated using short tandem repeat (STR) profiling by Microread Gene Technology (Beijing, China). The immortalized nasopharyngeal epithelial cell line (NP69) was cultured by defined keratinocyte-serum free medium (Gibco; Thermo Fisher Scientific, USA) at 37 °C and 5% CO 2 16 . The human NPC cell lines (CNE2, HNE1, HNE2, 5-8F, 6-10B and HONE1) were cultured in DMEM medium (Biological Industries, Israel) supplemented with 10% fetal bovine serum (Biological Industries, Israel) at 37 °C and 5% CO 2 .…”

Deciphering the Role of Epstein–Barr Virus Latent Membrane Protein 1 in Immune Modulation: A Multifaced Signalling Perspective

“…These interactions not only downregulate IFN signalization but also oppose the repressive ability of IFN- α/β in the case of EBV reactivation [ 54 , 55 ]. In contrast, latent EBV proteins like EBNA1 and LMP1 enhance STAT1 phosphorylation [ 56 , 57 ]. In addition to STAT1 and 2, another member of that family plays a role in cytokine signalization.…”

“…However, the majority of LMP1’s impact on cellular homeostasis is achieved via the C-terminal domain and its three functional subdomains or C-terminal activating regions (CTAR1, CTAR2, CTAR3). The CTAR1 domain contains the PxQxT motif (aa 204–208), which is necessary for the interaction of LMP1 with tumour necrosis factor receptor-associated factors (TRAFs); the last three amino acids in the CTAR2 region form the YYD motif (aa 384–386), which is important for interaction with the tumour necrosis factor receptor type 1-associated death domain protein (TRADD) and BS69, a multi-domain-containing cellular protein, while the CTAR3 region (aa 275–330) is a proline-rich region located between CTAR1 and CTAR2 which was shown to successfully bind Janus kinase 3 (JAK3) [ 11 , 57 , 100 , 101 , 102 , 103 ].…”